As disclosed in U.S. Pat. No. 3,821,383, aldose reductase inhibitors such as 1,3-dioxo-1H-benz[d,e]-isoquinoline-2-(3H)-acetic acid, and its derivatives, are useful as inhibitors of aldose reductase and alleviators of diabetes mellitus complications. Spiro-[chroman-4,4'-imidazolidine]-2',5'-dione and spiro-[imidazolidine-4,4'-thiochroman]-2,5-dione and their derivatives, disclosed in U.S. Pat. Nos. 4,130,714 and 4,209,630, are also indicated as being useful in this regard. Certain spiro-polycyclicimidazolidinedione derivatives from U.S. Pat. No. 4,181,728 have been demonstrated to have inhibitory activity against aldose reductase and polyol accumulation. U.S. Pat. No. 4,117,230 describes a series of spiro-hydantoin compounds which include the 6-fluoro and 6,8-dichloro derivatives of spiro-chroman imidazolidmediones. Spiro-fluorenhydantoin and its derivatives are disclosed in U.S. application Ser. Nos. 368,631 and 368,630, filed Apr. 15, 1982, as being potent human and rat aldose reductase inhibitors which prevent polyol accumulation in lenticular and nervous tissues of diabetic and galactosemic rats and prevent cataract and nerve dysfunction in diabetic rats. Pan et al, J. Med. Chem. 7, 31-38 (1964), described halogenofluorenes as potential antitumor agents, and Pan et al, J. Med. Chem. 10, 957-959 (1967), describes spiro [fluoren-9,4'-imidazolidine]-2',5'-diones as potential antitumor agents.